Measured stretch, tension distributing machine



Feb. 14, 1939. c. H JOHANSON MEASURED STRETCH; TENSION DISTRIBUTINGMACHINE Filed Dec. 14, 1936 ,3 ShGGtS-Sht l Feb. 14, 1939.

MEASURED STRETCH. TENSION DISTRIBUTING MACHINE c. H. JOHANSON 2,147,039

Filed Dec. 14, 1936 3 Sheets-Sheet 2 m. wsw Tan ,Ja'imnson Feb. 14,1939. C H, JQHANSQN 2,147,039

MEASURED STRETCH, TENSION DISTRIBUTING MACHINE max 70R, Jziawzsa 7Patented Feb. 14, 1939 PATENT OFFICE MEASURED STRETCH, TENSION DISTRlBUT- f ING MACHINE Carl Hugo J chanson, Los Angeles, Calif., assignor toOlivia S. Johanson, Los Angeles, Calif.

Application December 14, 1936, Serial No. 115,706

'12 Claims.

This invention is an apparatus and a method for preparing stretchableand contractive sheet material, of low elastic factor, for the cuttingtherefrom of given pattern pieces by the use of pat-' tems or dies. Theinvention is related to the class of invention generally shown in- U. S.patent application Ser. No. 96,415 to which reference is made fordisclosure of the old practice of hand stretching of glove skins for thecutting of glove blanks.

In picking up a skin from a supply stack an ope'rative (in a glovefactory) will scan the skin for shape, size, holes and other defects andthen determine whether it shall be first stretched from neck to rump, orfirst from flank to flank across the back. The stretch from neck torumpwill herein be called the lengthwise stretc and from flank to flank willbe called the cross- Wise stretch. In either case the skin, or otherappropriate material being treated, will contract transverse to thedirection of the applied tension.

If the skin is properly tensioned or stretched one way all over thecontracted width or direction is supposed to contain in each given unit,say three-fourths of an inch, across the direction of tension, a latentor possible stretch of onequarter of an inch, as an example, so thateach three-quarters of an inch across the stretched goods or skin may becounted as an available inch of leather. By the old hand stretchingmethod it is practically impossible to even fairly set uniform stretchall over the skin, for many reasons. One is that only a comparatively;small zone of the skin can be stretched betweenthe operatives hands inone gripping of the opposite edges of the skin, and repeated, changedgrips must be taken to work completely across the skin, with noreliability of uniformity in the stretched skin.

Also, in every skin (glove stock) it is known that a zone from the neckto the rump is the thickest, and that it gradually thins toward'theflanks; that is, the stomach area of the skin. An object of thisinvention is to provide a method and apparatus whereby this differencein the thickness is taken into consideration and whereby the skin is sostretched that it will have a uniform, substantially measured, latentstretch evenly distributed throughout. That is, a given unit of measureacross the stretch will contain, in any portion of the skin, an'am'ountof possible or latent stretch equal to that of any other portion.

From this it will be seen that if the operative works the skin properlyin accord with the method and sets the skin so that a given unit ofmeasure will have an inherent, uniform stretch value all over the skin,then, by the use of a cutting pattern or of a cutting die which isconstructed on a corresponding unit scale, the whole skin may be cutinto pieces all of which will be of the same latent stretch and a truesize glove will be had in the ultimate product. Reference is made to theprovision, in this invention, of pattern guides, dies or forms whosewidth or size number is predicated on a measuring unit which correspondsto the unit of measured stretch; say an inch of leather for eachthreequarter inch across the stretch direction of the 10 prepared skin.

It is understood that different tensions will be employed in settingdifferent skins according to the variance in the quality or stiffness ofthe skin.

It is an object to provide means for subjecting the entire central backzone from the neck to the rumip to a firm, uniform transverse tension toinitially reduce its thickness and then to work the tensioning meansoutwardly toward the flanks While the whole intervening skin betweengripping devices is subjected to a uniform tension in a plane from endto end of the skin; provision being made to slip the skin between thetensioning means during its operation.

Further, an object is to provide means whereby to subject the thicker,central neck-to-rump, narrow, back strip of the skin to a higher degreeof tension, when stretching the skin lengthwise,

than is applied to the'portions of the skin from said strip or back zoneto the edges of the side flanks, and still to provide means which willact in one operation entirely across the skin from flank edge to flankedge preferably in a plane.

Also, an object is to provide means operative during the stretchingprocess of a skin to tend to work out wrinkles by a spread-effect on thegoods passing into the active tensioning means.

Another object is to provide, in one machine, means to accomplish bothlengthwise and crosswise stretch, in successive operations, althoughseparate machines are here provided for the accomplishment,respectively, of only one of the stretching functions,

The invention consists in certain advancements in this art as set forthin the ensuing disclosure and having, with the above, additional objectsand advantages as hereinafter devolped, and whose construction,combination and details of means, and manner of their operation, and thesteps of the skin working method, will be made manifest in thedescription of the herewith illustrative embodiment; it being understoodthat modifications, variations and adaptations may be resorted to withinthe scope, principle and spriit of the invention as it is more directlyclaimed hereinbelow.

Fig. 1 is a plan of a skin before stretching. Fig. 2 is a plan of apreferred form of machine for lengthwise stretch of a skin, and Fig. 3is in part a central longitudinal, vertical section thereof. Fig. 4 is across-sectional detail of a skin gripper and its co-acting, bladed benchmedially of its length. Fig. 5 is a plan of a preferred form of machinefor cross-stretch of a skin; that is, transverse to its thick,longitudinal, central back zone.

Fig. 6 is a vertical, medial, longitudinal section of the sliding leavesand their skin gripping devices (the drive mechanism being omitted).-"Fig. 7 is a vertical, medial sectional detail of -a tensioning leafprovided with both a transverse or cross-stretching means and alengthwise stretching means, and Fig. 8 a p'l'an of p'a'r-ts of-thelengthwise-stretching gripper. Fig. 9 Ba plan, and Fig. 10 a face viewof a part of a' gripper showing the-facing thereof to effect a spreadingtendency of the goods beingwork'ed on. "Fig: 11 is a plan-of afragm'entof charted skin and applied die; Fig. 12'is a-plan of-a gripper stripwith one form of spring means to exert different degrees of pressurefrom the; central back toward thesofter flanks-of a: skin, and Fig.liv'showsa modified form thereof. Fig. 14 is a cross-section throughoneend of the device of -Fig. 12. "Figs. 15 and 16 are front and sideviews; respectively, of another form= ofv the lengthwise stretchingmechanism.

a In Fig-.- 1 is s'hownaskinindicated asa whole S; the thickest centralback zone is indicatedat T'extending from neck to rump and one step ofthe "instant method is to uniformly stretch this zone transversely toasuitable-degree as indicated by the line T. This isdone by means firmlygripping the skin alongpa'rallellines' from neck 35" to rump" and movingthe gripping m'eans apart substantiallywi thout slip ofthe gripped skin.

To accomplish this preliminary crosswise stretch there is shown inFigs.5 and 6, the table 2 of a machine including an opposed pair ofsubstantial slides 3 and 4, of U shape plarr and which are movableinwardly toward each other between their guide and supporting rails 5-5.

Fixed, upstanding, rigid skin-flexing blades 6" and I present straight,top edges'transversely above and along the'inner' portions of the-slides3-4 and are movable with and bythe slides into the desired spaceddistance to be"overla-id by the back'zone'Tof an applied skin' to bestretched; the adjusted space-of the-blades-6-"-'1being de teri'nined'by the varyingwidths-of the s'aid 'zone indifferent skins.'Along" theouter-sideface of each blade isfiked apressurestri or benchB'over which the flanks F- -F are draped in arranging the skin to bestretched; the length' of the benches and their blades-being such as toaccommodate the average large skin in a supply batch of 'glove'material,"for'instance.

Each slide 3--4 is provided with means to be moved into pressureapplying" relation with the relative straight-edged blade" B-'I and itsback strip or bench 8 for the purpose of gripping the interposed skinand placing it under tension by a'relative separating or outward motionof the slides on the table 2, whichmay be accomplished by manual effortor by power means as later described with respect to Fig. 3. "Thegripping means of Figs. 5, 6 and 7 include a straight, transversepresser bar l0 having hinge pivots I l permitting the upward swing ofthe bar from its blade bench for'the insertion of the skin to be worked;and preferably the effective face of the gripping bar llL'or ofthe'b'ench 8, or both, is provided with a suitable friction strip 12,Figs. 9 and 10, as of rubber or other suitable material.

After the skin S'has been arranged over the inwardly shifted slides 34and between the opened gripper and presser bars In these are moved intoclosed position on the interposed portions' of the skin and caused togrip the skin with a suitable degree of pressure by means providedforsuch function. The pressure applying means ofFigs. 5-6 is a clamplever l3 pivoted at M onthe relative slide of each bar l0 and having aturnable screw l5 adapted to be run into a fixed nut l6 in theslide-top; the lever l3 being engageable with a rigid part ll of therelated presser bar I when the latter is in applied position and'theclamp lever is tipped over or astraddle the lug I! to bring the screw I5into engagement with the fixed nut I6.

The presser'bars are-at first set so tight on the skin that it cannotslip'while the slides 34 vare forced outward or apart to initiallystretch the back zone 'T to reduce its thickness to the desired'degree;the gripping means being effective from neck to rump and tensioning theskin transversely while gripped from end to endin a smooth plane. 1After this initial, non-slipping, pulling grip on the skin is completed.then the pressure is released at the pressure control device'or lever I3of each slide to! permit the-engaged portions of the skin to slidebetween the gripping bars and their benches and over the relativestraight blades 6 and I so that the whole portion ofv the skin from endto end and from blade to blade is evenly tensioned and lengthenedtransversely, meanwhile contracting transverse to the line of stretch.The degree of contraction is carefully controlled and measured by theoperative so that each unit of measure transverse to the direction ofstretch may be given or caused to contain a desired amount of stretch orleather in a blank which is cut from the skin on a size unit ofmeasure-based on the adopted unit'of measure of the contracted skin. 7

While it may suflice in some class of glove work tostretch the skin S inone direction only, according to the condition, size and quality of agiven skin, it is preferably given a second stretch which is in adirection transverse to the first stretch.

In Figs. 2, 3, '7 and 8 are illustrated means adapted for the stretchingof a skin lengthwise, that is, from neck N to rump R, Fig. 1. Since thelongitudinal zone T is the thickest or toughest it is desirable that itbe given a higher degree of lengthwise tension than is imposed on theside or flank portions F, and also that the degree of longitudinaltension be graduated downwardly from the center of the skin outwardly tothe flank edges, because the skin gradually thins that way.

To that purpose the tensioning slides 3 and 4 Figs. '2 and 3, have theirstretching blades 6* and I arranged in a regular arc inwardly toward thecenter line of the table 2, with the top, effective edges in acommonplane for an overdraped skin S to be stretched from neck to rump;each blade having an outer pressure bench 8 against which the interposedskin is pressed. In this case the presser means includes a stiffsegmentZll w'hose inner or effective edge 2! is curved to match thecurvature of the relative blade and bench device li -8 and is preferablyprovided with a friction strip I2, above mentioned. The presser segmentis movably mounted, as by slide pins 22 working in a bridge 23 which, inturn, is slidably mounted on its relative main slide, as 4*, or 3*, sothat the bridge 23 may be quickly moved in or out with its slidablegripping end pressure element or segment 20, to grip or release theinserted skin. Clamp jaws at the ends of the bridge 23 (on each slide)may be closed on contiguous slideways 26 to hold the bridge in itsinwardly adjusted position.

In order to vary and control the amount of gripping pressure of thesegments 20 on the engaged skin S, in the machine, spring means 21 areinterposed between the segment and its bridge and a control screw 28 isadjustable in the bridge (ineither slide) to regulate the degree ofpressure of the spring 21 against the presser segment when this is inpressure position on skin on the relative, curved blade 6 or 1 It willbe seen that the stretching tension is greatest along the shortest linebetween the opposed curved gripping means on the slides 3*--4 and thatthis tension decreases on parallel lines running from neck to rump ofthe skin as the lines increase in length between the reversely curved,opposed gripping segments 29, shown in dotted lines in l A fifty poundpull on the shortest or central *line from one segment to the other willhave less stretching effect on the parallel lines of greater length oneither side thereof; the efiect decreasing as the distance increasestoward the edges of the flanks of the engaged skin.

Various suitable means'may be employed to con currently shift the slidesof the machines here shown outwardly or inwardly. Fig.8 shows the slides3 4*- as having fixed nuts 30 engaging reverse pitch screws 31" ofacommon shaft on which is fixed a drive element 32,-connected by a beltor chain 33 to a counter-shaft 34 which is driven by a suitablyconnected motor 35; preferably of reversible electric type, undersuitable control by the operative as to speed and direction of drive ofthe screw-shaft 3|. The drive mechanism is suitably mounted in the frameof .the table 2 of the machine.

Fig. 4shows in about full size the details of assembly of a renewable,friction strip l2 of a presser element, as segment 20.

The friction strip I2, whether mounted on the 7 blade, or on the bench,or on the efiective edge of the moveable presser device, It! or 20, hasits face provided, preferably,with diagonal, shallow corrugations, HFigs. 9 and 10, which are so pitched that they have a re-actingtendencyto press the engaged skin outwardly from the center line of tension on askin, as indicated at L, Fig. 10 and from which line the diagonalcorrugations are reverse.

In Figs. 7 and 8 there is illustrated a machine .slide 3 provided withboth straight-edge tensiening device as Iii-45, of Fig. 5, and acurvededge tension device as 6 2ll the part 20 being a segment whoseends are hinged at 20 on the relative slide 3 this segment having'asuitable clamp 20 whereby it may be set with desired pressure againstthe cooperative skin supporting blade and bench device on the slide. InFig. '7 the clamp nut of member I!) is shown in detached position. If askin is applied to and stretched by the use of the outer devices Zil -iiit overlays the closed inner devices l06 without interference.

A modified form of presser segment is shown in Fig. l2 as including astrip 40 which is supported by a set of thrust springs 4! each of whichdecreases in strength according to its position outward from the centerof the segment, whereby to secure a gradually reduced pressure on anengaged skin S from the back zone T to the The same decrement inpressure of the strip 40 may be obtained as shown in Fig. 13 by use ofsprings 42 each of the same strength but are spaced closer together,along the arched strip, inwardly from the outer, flank stretching endsof the strip. The strips 40 are attached by sliding bolts 43 to theirslide mounts 44.

A further variation of the form of the stretching machine is depicted inFigs. 15 and 16 where segmental wings are pivoted on a hinge 5| in asuitable frame 52. The outer or swinging ends of the wings are connectedby a pair of toggle links 53 attached to a truss bar 54 connected to anactuating lever 55, operable by desired means to raise or lower the bar54 to spread or contract the wings so as to tension a skin S draped overthe top edges of the wings and gripped by presser means, as of the kindabove described. This machine, by reason of the convex curve of its topedges and relative gripping means functions to apply greater tensionalong the line of the thick back T of a skin S, Fig. 1, than along theflanks from neck to rump of the skin since the crown or top of thearched edges of the wings move a greater distance, in the same action bythe toggle, than the ends of the arcs of the wing edges, about the hingeaxis 5|.

It will be seen that by reason of the pre-stretching of the thick backzone T transverse to its length between the straight line gripping andpresser means extending from neck-to rump of the skin, and by reason ofthe subjection of the skin to lengthwise stretch between the peculiarcurved-line gripping and presser means with a tension which diminisheson lines from neck to rump in zones on each side of the back zone T,that the operative can produce rapidly and accurately stretched skinsthat have uniformly all over a desired measured stretch of goods, thatis a known amount of latent leather to work out in true size gloves whenthe blanks are cut from the skin by the use of dies which are calculatedin units of size which correspond to the adopted unit of measure acrossthe contracted direction of the prepared skin.

In Fig. 11 a fragment of the skin S is shown charted into oblong areas Cwhose narrow dimension indicates the stretchable unit of measure alongwhich a die, pattern or form member D is laid for the cutting or markingout of a relative glove blank, it being understood that the member D isbased on a width, size scale corresponding to the unit width or narrowdimension of the oblongs of the areas C. That is the size number of agiven glove, in inches across the glove,'is utilized in counting thenumber of the contracted areas C, plus one more for silking andstitching, and since the skin has been uniformly contracted so that.each oblong will measure, say of an inch and will be stretchable up toan inch, a die which is made on the measure of the contracted unit willprovide for the ultimate stretch of the cut blank to make a true size orproperly fitting glove.

The U-shaped plan of the table slides carrying the stretching meansenable the operative to stand in close to the several operative parts ofthe machine for the facile tucking of the skin in place over blade edgesand under the adjustable gripping or presser devices.

What is claimed is:

l. Stretching sheet-like material by gripping it along continuous,opposed, arcuate lines thereof and shifting the lines of grippingpressure apart to first stretch the skin all over in one direction '75onlyrfrom; side: to side between::.ungripped ends;

said lines having such relationthatas the gripped lines of'thesheet areshifted apart a greater'tension is created in'an-intermediate'zoneacross the sheet than is set up in zoneslateralto the intermediate zone,and then subjecting the stretched skin to the same mode of treatment onlines transverse to the first stretch to contractthe first lines ofstretch.

2. Stretching :sheet-like material by applying gripping pressure alongcontinuous lines parallel to a given zone of the material andcross-tensioning the material by relative separation of the linesofpressure or grip without slip, then reducing the gripping pressure andcontinuing the separation to cross stretch accompanied by a slipping ofthe material under the gripping pressure, and then subjecting the saidstretched material to tension in a direction across the first stretchand in such amanner that the stress is highest along a central line, inthe direction of the stretch, and which stress gradually diminishes in'portions" lateral and parallel to the said central line.

3. A machine for stretching glove skins or other 25t-material, includinga support having a pair of opposed slides operative thereon in a commonplane and each slide having an incurved, outer bench edge transverse totheir line of motion, the said r edges being concaved toward each otherand over -which a skin may be draped from one slide to the other, meansfor relatively separating the slides while so draped, and presserdevices having skin engaging edges convexly 'curved toward each W otherand complementary to the opposing bencfi edges of said slides'whereby togrip the skin in curved lines along the outer edges of the slides and tosubject the skin to different degrees of tension from slide to slide asthese are moved apart, said slides carrying respective, transverse-blades presenting top edges over which the draped skin is flexed anddrawn as it is permitted to slide relative to its gripping devices.

4. A machine for stretching glove skins or other material including asupport having a pair of op- 1-posed slides operative in a common planeand having bench edges transverse to their line of motion and over whichthe skin may be draped from slide to slide, means for relativelyseparating the slides while so draped, presser devices having -skinengaging edges complementaryto the opposing bench edges of said slideswhereby to grip the skin in lines along the outer edges of the slidesand to subject theskin to tension as the slides are moved apartrelatively, and said slides -carrying respective, transverse bladespresenting top edges over which the draped skin is flexed and drawn asit is permitted .to slide as to its relative gripping device. V m 5. Amachine as in claim 14,. and in which the presser devices are slidably.guided on and outwardly movablelby and .with respective slides duringstretching operation. a

6. In a machine of the class described, a pair of slides movableinacommon' plane, means for motivating theslides, and said slides having,each, a mechanism forgripping 'an interposed skin alongelongate,circuitous lines :from edge to edge of the skin andof such contour that,as the 7 ,-;mechanisms are moved apart relatively by theslides, the tautzone of the skin is subjected to lines of tension varying at differentareas between the gripping lines; said slides. having outer edges overwhich the skin is drapable and ;;said mechanismsbeing slidably mountedto close onsaid draped skin. and movable ioutwardly by r and with therelative slides.

7. A skin or sheet stretching machine including a support, a pair ofslides movable in opposition thereon, means for motivating the slides,bench parts on the slides each with a respective straight-edge pressermember to slidably grip a skin draped from slide to slide over the benchparts, and each slide having parallel to the bench part a bladepresenting a supporting edge over whichtheskin flexed during stretchingoperation; said members having smoothgripping faces, said support havingan intermediate pocket into which thematerial, draped between thepresser members and their bench parts, hangs while draped for stretchingoperation,

8. A machine asin claim '7, and in which said presser member is providedwith a yieldable facing medium and said bench parts present acomplementary, smooth, firmv face to said presser members for slidingefiiciency.

9. In a sheet stretching machine, a pair of cooperative grippingelements separable for insertion of the sheet and closeable to slidablygrip it on a continuous line, and a cushioning medium interposed betweensaid parts as a facing to engage the sheet; and which medium includes afacing strip along one of said elements and a bank of springs interposedtherebetween and operative to exert difierential pressure on the stripin degree decreasing outwardly from the center thereof.

10. A machine for stretching glove skin or other desired material,including oppositely spaced members presenting faces to support and overwhich the skin is draped, a relative skin bending blade in inwardly,fixed association with each of said members, presser means for engagingthe skin continuously along the said faces, and for tensioning it fromblade to blade, means for regu lating the degree of pressure of saidpresser means and providing for skin slip during stretching, and meansfor relatively separating said members while the skin is gripped theretoby the presser means.

11. Glove skin stretching mechanism including oppositely spaced, movableslides having benchforming members and skin bending blades fixed ingiven relation to each member and presenting spaced top edges to supportthe skin extending from one member to the other and said members havingouter supporting faces for the applied skin extending to and along saidedges for the length or width of the skin to its opposite edges, andmeans to press the applied skin extending from one to the other of saidmembers to the outer faces thereof so that when the members and saidmeans are shifted apart without slipping of the skin therebetween thelength of the skin held between the said members is uniformly tensionedfrom member to member; the presser means being adjustable to allow theinterposed skin to slip therebetween after an initial tension operationwithout slip so that the whole of the skin gripped along continuouslinesfrom one edge to the other, of the skin, will be tensioned equallybetween the gripping means cooperating with said members.

12. Stretching sheet-like material by applying gripping pressure alongcontinuous opposite lines

